Yes, it doesn't work out of the box. Proton games literally won't launch. You need to run this command (at least on atomic distros):
flatpak permission-set background background com.valvesoftware.Steam yes
https://github.com/AeonDesktop/Project/wiki/Troubleshooting#steam-flatpak-opens-but-cant-start-games
Mangohud also doesn't work without modifications, as well as a couple games having absolutely abysmal framerates like rocket league.
Gamemode doesn't work AFAIK
It is a worse experience in general, but works for a lot of people.
And for any of the people saying "he changed".
One of his most recent "philanthropic" ventures was to partner with Nestle (good start) to "modernize and increase yields" of the dairy industries in impoverished countries.
The two organizations then sold modern (likely non-servicable) equipment and entrenched them in corporate supply chain systems geared towards export and making it much harder to trade locally (not sure how that part worked, but was in what I read).
For a grand total of........ 1% increased dairy yields.
Then 3-4 years later they pulled out, leaving heavily indebted farmers without the corporate supply chains and delivery systems they were forced to switch to, and making it very difficult to switch back to the old ways of working, so they can't sell nearly as much locally.
Who do you think will buy up those farms when the farmers go bankrupt and have to sell ar rock bottom prices.